Gerald A. Beathard

Salvage of the nonfunctioning arteriovenous fistula

Two factors are necessary for an arteriovenous fistula (AVF) to be usable as dialysis access. It must have adequate blood flow, and it must have a size that will allow for cannulation. An AVF can remain patent in the face of relatively low blood flow. For effective dialysis, the AVF only has to deliver a blood flow that is marginally greater than the pump rate. Unfortunately, dialysis may not be technically possible in these cases with lower flow because the AVF does not mature sufficiently to a size adequate for cannulation. In this prospective observational series of 63 patients, failure of AVF development was the result of venous stenosis and/or the presence of accessory veins (venous side branches). The presence of these anomalies could be diagnosed by physical examination. After documentation by angiography, the patients were treated with angioplasty, venous ligation, or a combination of both. Three levels of venous ligation were performed depending on individual requirements: ligation of accessory veins (AVL), ligation of the median cubital vein, and temporary banding of the main fistula itself. The determining factor was the appearance of the fistula after each of the procedures was accomplished relative to potential for cannulation. Of these 63 patients with nonfunctional fistulae that ranged in age from 33 to 418 days, access was salvaged in 52 patients (82.5%). This included 9 of 12 patients who required repeat procedures. The results of this study validate angioplasty and AVL as therapy for the salvage of AVFs that fail to develop.

Early Arteriovenous Fistula Failure: A Logical Proposal for When and How to Intervene

A significant number of arteriovenous fistulae (28 to 53%) never mature to support dialysis. Often, renal physicians and surgeons wait for up to 6 months and even longer hoping that the arteriovenous fistula (AVF) will eventually grow to support dialysis before declaring that the AVF has failed. In the interim, if dialysis is needed, then a tunneled catheter is inserted, exposing the patient to the morbidity and mortality associated with the use of this device. In general, a blood flow of 500 ml/min and a diameter of at least 4 mm are needed for an AVF to be adequate to support dialysis therapy. In most successful fistulae, these parameters are met within 4 to 6 wk. Most important, commonly encountered problems (stenosis and accessory veins) that result in early AVF failure can be diagnosed easily with skillful physical examination. Recent studies have indicated that a great majority of fistulae that have failed to mature adequately can be salvaged by percutaneous interventions and become available for dialysis. Early intervention regarding identification and salvage of a nonmaturing AVF is critical for several reasons. First, an AVF is the best available type of access regarding complications, costs, morbidity, and mortality. Second, this approach minimizes catheter use and its associated complications. Finally, access stenosis is a progressive process and eventually culminates in complete occlusion, leading to access thrombosis. In this context, the opportunity to salvage the AVF that fails early may be lost. This report reviews the process of AVF maturation and suggests a strategy for when and how to intervene to identify and salvage AVF with early failure.

Fistula First Breakthrough Initiative: Targeting Catheter Last in Fistula First

An arteriovenous fistula (AVF) is the optimal vascular access for hemodialysis (HD), because it is associated with prolonged survival, fewer infections, lower hospitalization rates, and reduced costs. The AVF First breakthrough initiative (FFBI) has made dramatic progress, effectively promoting the increase in the national AVF prevalence since the program’s inception from 32% in May 2003 to nearly 60% in 2011. Central venous catheter (CVC) use has stabilized and recently decreased slightly for prevalent patients (treated more than 90 days), while CVC usage in the first 90 days remains unacceptably high at nearly 80%. This high prevalence of CVC utilization suggests important specific improvement goals for FFBI. In addition to the current 66% AVF goal, the initiative should include specific CVC usage target(s), based on the KDOQI goal of less than 10% in patients undergoing HD for more than 90 days, and a substantially improved initial target from the current CVC proportion. These specific CVC targets would be disseminated through the ESRD networks to individual dialysis facilities, further emphasizing CVC avoidance in the transition from advanced CKD to chronic kidney failure, while continuing to decrease CVC by prompt conversion of CVC‐based hemodialysis patients to permanent vascular access, utilizing an AVF whenever feasible.

The nephrotic syndrome associated with neoplasia: An unusual paraneoplastic syndrome: Report of a case and review of the literature

The nephrotic syndrome complicating malignancy in the absence of renal vein thrombosis, amyloid or neoplastic infiltration of the kidney is an unusual occurrence. A case of diffuse, well differentiated, lymphocytic lymphoma and lipoid nephrosis documented by light microscopy, electron microscopy and immunofluorescent studies is reported. A review of the literature revealed 76 case reports in which the nephrotic syndrome was associated with neoplasia. The most frequently associated neoplasms are Hodgkins disease, various carcinomas, nonHodgkins lymphoma and leukemia in descending order. The most frequent renal lesion in patients with the nephrotic syndrome associated with various carcinomas is membranous glomerulonephritis (81 per cent) as opposed to patients with lymphomas or leukemias who have predominantly lipoid nephrosis (60 per cent). The evidence is reviewed suggesting that the lesions in membranous nephropathy are immunologically mediated by tumor or viral antigen-antibody complexes and in lipoid nephrosis perhaps by a defect in t-lymphocyte function.

Infection Associated with Tunneled Hemodialysis Catheters

The use of tunneled dialysis catheters to deliver hemodialysis treatment may be associated with major problems. For this reason their use should be minimized as much as possible. Infection is the most serious of these problems. This complication causes very significant morbidity and mortality and has emerged as the primary barrier to long‐term catheter use. Bacteremia is the most serious type of infection associated with catheter use. It can result in metastatic infection and even lead to death of the patient. Prophylaxis is important to decrease the risk of infection. The use of an antibiotic ointment at the exit site until it has healed and the long‐term use of a dressing to cover the exit site are effective in decreasing the incidence of exit‐site infection. With optimal catheter‐use management, it should be possible to reduce the incidence of catheter‐related bacteremia (CRB) to a level in the range of 1/1000 catheter days. Antibiotic and antimicrobial locking solutions show promise and may, if verified in appropriate clinical studies, prove to be important adjuncts to the management of catheter‐dependent patients. Aspirin has been shown to have anti‐staphylococcal activity and warrants further clinical evaluation. The diagnosis of CRB is based upon positive blood cultures in association with typical clinical features. If a simple routine blood culture is positive, along with a high clinical probability based upon the patient’s signs and symptoms, the sensitivity and specificity of the diagnosis is greater than 75%. CRB is in reality a biofilm infection and must be treated as such. Treatment needs to focus on appropriate systemic antibiotics which should be continued for a minimum of 3 weeks and catheter management to remove the biofilm. Catheter exchange has been shown to be effective and should be performed based upon the clinical presentation of the patient. While treatment with a combination of systemic antibiotics and antibiotic locking solution may be effective for gram‐negative infections, this approach does not appear to be a good choice for Staphylococcus aureus CRB.

An Algorithm for the Physical Examination of Early Fistula Failure

Evaluation of a newly created fistula 4–6 weeks after surgery should be considered mandatory. If the fistula is going to become adequate for dialysis, it will be apparent at this time. This evaluation can be accomplished by physical examination. However, it must be performed by someone who is knowledgeable. Using a systematic approach facilitates the evaluation and ensures that a problem is not overlooked. Once it is determined that the fistula is dysfunctional, the case should be immediately referred for management to an interventionalist who is experienced in dealing with early fistula failure. The majority of these cases can be salvaged.

Physical Examination of the Dialysis Vascular Access

The hemodialysis vascular access is associated with complications that result in patient morbidity and mortality and add considerably to the cost of managing chronic renal failure. The annual cost of maintaining vascular access in the United States is approaching one billion dollars (1). This represents only the tip of the iceberg, however, Problems that derive both directly and indirectly from these complications result in a major proportion of the hospitalizations required in this frequently hospitalized population of patients (2). In recent years a great case has been made for establishing a quality assurance program to detect the access at risk and the prospective implementation of procedures to increase access longevity. Considerable investigative effort has been expended in search of the best method or the most effective technique for detecting the access at risk. Much has been written concerning recirculation, venous pressure, and access flow. Concern has been expressed regarding cost, convenience, and effectiveness. In this search for the “Holy Grail,” the oldest and most time-honored investigative tool available to the diagnostician has been largely ignored: the laying on of hands, i.e., physical examination. Physical examination has not been totally ignored. In a brief comment in the Dialysis Clinic section of this journal (3), we reported finding a 91.7% incidence of significant (> 50%) venous stenosis in a series of 328 angiograms performed after a screening physical examination. In his 1994 review of techniques for the prospective detection of venous stenosis, Depner (4) directed attention to the importance of this approach. Trerotola et al. ( 5 ) concluded that physical examination was a good screening test for ruling out the low flows associated with impending access graft failure. After comparing the various methods advocated for screening dialysis access grafts for venous stenosis, Safa et al. (6) found abnormal physical examination findings to be the most common sole indicator of graft dysfunction. Except for these, the literature is scant on the issue of actually touching, looking at, and listening to the patient’s vascular access in order to gain useful information. Nevertheless, I am convinced that this is a useful and reliable technique. It is certainly easily done and inexpensive. Additionally,

Strategy for Maximizing the Use of Arteriovenous Fistulae

Increasing the use of arteriovenous fistulae in dialysis patients requires a specific strategy. In order to properly select patients for an arteriovenous fistula (AVF), it is essential that the nephrologist become knowledgeable about the subject and that an organized approach be followed. Both the arterial and venous systems must be evaluated. Evaluation of medical history, general physical examination, specific physical examination related to the vasculature of the extremity, vein mapping and duplex ultrasound studies are all important. It is very important to assess the size of the vessels involved. Although a newly created AVF should be allowed to fully mature prior to use, failure to develop should be evaluated early. Many cases of early failure can be successfully salvaged. Even if the patient has an arteriovenous graft, they should be evaluated at the time of every graft failure for the possibilities of creating a secondary AVF.

Catheter Thrombosis: CATHETER THROMBOSIS

Catheter malfunction due to poor flow is a common problem. When it occurs early, the cause is generally technical. Late occurrences are most often related to thrombus formation. Several types of thrombus may be seen, differing by location and supposed mechanism of formation. The most common offender, however, is the fibrin sheath thrombus. Prevention of catheter malfunction is an endeavor that continues to beg many questions. Catheter malfunction should be treated early to avoid inadequate dialysis. In the past, urokinase was a highly valuable aid to the nephrologist in managing this problem. Since this agent became unavailable a suitable alternative has not emerged. Recombinant tissue plasminogen activator (tPA) seems to be the most likely candidate for this role; however, it is not currently available in a packaging form that is optimal for this purpose. Currently, catheter exchange appears to be the best available alternative for this problem, which cannot yet be resolved by simpler means.

American Society of Diagnostic and Interventional Nephrology: Section Editor: Stephen Ash: Catheter Management Protocol for Catheter‐Related Bacteremia Prophylaxis

This study reports a prospective observational study in which an infection prophylaxis protocol based on the National Kidney Foundations Kidney Disease Outcomes and Quality Initiative (NKF‐K/DOQI) guideline 15 describing guidelines for the care of the tunneled dialysis catheter at the time of catheter hook‐up for dialysis was used. Catheter‐related bacteremia (CRB) incidence data were collected for a 24‐month study period and compared to retrospectively collected control data for the immediately preceding 9 months in the same patient population under the same conditions except for the prophylaxis protocol. The incidence of CRB fell from an average level of 6.97 per 1000 catheter‐days during the control period to an average of 1.68 during the study period. This change was statistically significant. Although the lowered incidence required 6 months to reach its maximum, the decreased infection rate was sustained. The average incidence during the last 18 months of the study period was 1.28 per 1000 catheter‐days. Staff compliance with the protocol did require repetitive education and assessment.